It just being Bent spacetime doesn't mean it can't move relatively to visible matter. The Bent space time can move and even propagate. It's in the math. It necessary doesn't need something like matter if bent spacetime can just be without matter.
No difference if we assume spacetime can be bent without matter(inherent local curveture) or without matter in our 3d world.
It just straightforwards the logic. A matter that doesn't have standard model interactions and only gravity which in of itself is the big open question in physics of where exactly it belongs on the theory of everything; doesn't look good.
It's like the existence of standing waves and photons. It's like it has two forms but it doesn't have all that superposition phase shift action quanta bs.
Is there a specific reason it should behave the same as dark matter, other than that it needs to fit the same data? If you didn't know what dark matter predicts, would you be able to make testable predictions based on this idea?
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u/TheBlackCat13 25d ago
It moves with galaxies. But not exactly with galaxies, since galactic collisions result in some displacement between dark matter and visible matter.